New Distribution Record and Taxonomy of Two Cucullaeidae Species (Bivalvia: Arcacea) from Thermal Beach, Thoothukudi, South East Coast of India

Arcidae are predominantly marine bivalves. Cucullaeidae are a small family of Arcidae with four living species (Huber, 2010). Two species of Cucullaeidae, Cucullaea labiata (Lightfoot, 1786) and Cucullaea petita (Iredale, 1939) were collected from Thermal beach, Thoothukudi, Tamil Nadu. The detailed systamatics, taxonomy and marked difference between these species are dealt with in this paper. The occurrence of two Cucullaea species such as Cucullaea concamerata (Martini) and Cucullaea labiata (Lightfoot) from Tamil Nadu coast was reported by Dey and Ramkrishna (2007). However, the exact distribution record and taxonomical description of these species are not available from India. Like other clams there are also commercially valuable species used as food in many countries. In this paper these two species are newly reported from Gulf of Mannar region of Tamil Nadu. These species are believed to be nearly extinct. The study area from where these species were collected was polluted with the effluents from thermal plants and saltpans. These species are highly disturbed due to climatic change and therefore strategies will be needed to conserve these species. The presences of these species indicate the rich marine bivalve diversity in the Gulf of Mannar region. The near extinction of these species should be viewed seriously and urgent steps should be initiated in order to conserve these species from further disappearance from the face of the earth for good.